The present invention relates to an apparatus for use in moving a control surface during operation of an aircraft.
A known apparatus for use in moving a control surface during operation of an aircraft includes an actuator which is disposed on a wing of an aircraft and is connected with the control surface. A flexible drive shaft connects the actuator with a source of power. A coupling is provided between the flexible drive shaft and the actuator. This coupling has a polygonal cross sectional configuration.
To obtain relative movement between the actuator and the flexible drive shaft, a locking interaction at polygonal surfaces of the coupling must be overcome. However, the locking interaction at the polygonal surfaces of the coupling requires a relatively large force to effect relative movement between the actuator and the flexible drive shaft.